Polishing wheels



, Sept. 27, 1955 J. MYER 2,718,737

POLISHING WHEELS Filed Nov. 2, 1953 /A/I/E/VTO/Q y @uwer 5V TTQR EY United States Patent O 2,718,737 POLISHING. j `Jack Myer, san rranisq.ca1if. j Application-November A2, 1953, SeriallNo. 389,591

' ,1.01am- C11fsl--la'aVv The present invention relates to a polishing wheel intended particularly for use in connection with a crankshaft grinder, such as is manufactured by Sunnen Products Co., of St. Louis, Missouri, and fully described in its pamphlet entitled: Information and Instructions for the Sunnen Model K Crankshaft Grinder.

This crankshaft grinder is used principally for grindin the surfaces of the connecting rod journals of a crankshaft, and comprises in its principal features a rotary shaft having a grinding wheel mounted upon the free end thereof to bear against the journal, means for rotating the shaft at high speed, a follower for holding the grinding wheel to the journal and a general frame structure allowing the rotating grinding wheel to follow the journal as the latter is revolved about the axis of the crankshaft.

This grinder can be used as a lathe attachment, or may be used directly on a crankshaft mounted in a motor vehicle.

The particular grinding wheel used in this machine is in the form of a thin-rirnmed cup engaging the surface of the journal and since thus the contact area between the wheel and the work is small and the wheel is free and unobstructed, comparatively little heat is generated during the operation.

After the grinding operation is completed, it becomes necessary to iinish the journal to a tine, glass-like surface. This operation cannot be performed by the grinding wheel, and heretofore it has become necessary to use some other means, apart from the machine, for finishing the journals, which was an awkward, time-consuming operation, particularly with the crankshaft mounted in the motor vehicle and the journal relatively inaccessible.

In the present invention it is proposed to solve the problems inherent in the finishing operation by providing a specially constructed finishing wheel which may be readily substituted for the grinding wheel of the machine under discussion and which will perform the finishing operation expeditiously and at a great saving in time.

The greatest obstacle to be overcome in the nishing operation is the generation of heat which would almost instantly tear and destroy an abrasive cloth applied to the journal at the speeds involved.

In the present invention, it is proposed to provide a polishing wheel with an abrasive cloth mounted upon one end thereof and bearing on the journal, the wheel being constructed in such a manner that it will conduct the heat away from the' cloth as rapidly as it is generated and will allow the abrasive cloth to be used, without injury, through many successive operations.

Further objects and advantages of my invention will appear as the specication proceeds, and the new and useful features of my polishing wheel will be fully dened in the claim attached hereto.

The preferred form of my invention is illustrated in the accompanying drawing, forming part of this specification, in which:

Figure 1 shows a perspective View of my polishing wheel;

l Figure,2,.a sideviewfof the-same@ Y Figure, 3,4 another. lperspective view, withthe ends-reversed;and j i Y i -Figure 4,V an axial` section through the `polishingzwlieell While I haveshownonly thepreferred `form-of invention, fit: should beunderstoodthat various changes orV modificationsmay be. madey within .the seope--o-fthe claim -hereto attached, without departing-.from the spirit of'therinvention'. i i i zi .Refer-ring` to the.. drawing, iindetail, my. polishing! wheel lcompri'ses i in` its principal features a `cylindrical bodyf having an axial threaded hole or bore 3 therein, with a sheet 4 of abrasive cloth secured upon one end thereof, the sheet being circular in form and substantially coextensive in diameter with the body, although it may slightly project beyond the periphery thereof.

The body is formed with a series of annular grooves 5 in the circumference thereof, so as to present a similar series of annular fins 6 adapted to radiate heat from the body at a fast rate when the body is rotated at high speed.

The body is preferably constructed of aluminum, which is highly heat-conductive, or any other metallic material having similar heat-conducting properties.

The body is of considerable length as compared with its diameter to present a large circumferential area as a heat-radiating surface, and its length and diameter should be related to carry off heat from the abrasive cloth when rotated at high speed, say 12,000 R. P. M. and with the cloth in polishing contact with the journal to be nished, to keep the cloth at operative temperatures.

By way of example, it might be stated that the body shown in the drawing has a diameter of one and threeeighths of an inch, and a length of seven-eighths of an inch.

The central bore of the body terminates, at the end carrying the abrasive, in a conical or tapered countersink 7, and the central portion of the abrasive cloth is preferably preformed to tit the countersink and to be clamped between the surface of the latter and the correspondingly tapered underface of the head of a screw 8 threaded into the bore.

The abrasive cloth is preferably cemented to the surface of the body, and the screw head is dimensioned for accommodation thereof in the countersink, with the top surface of the screw head disposed below the plane of the cloth, as shown, to leave a slight central depression in the latter surface.

The screw extends into the body only a certain distance, leaving the opposite end of the thread free for screwing on the actuating arm of the crank shaft grinder (not shown).

In operation, as applied to the Sunnen crankshaft grinder, after the grinding operation is completed, the operator merely unscrews the cup grinding wheel from the actuating shaft, and substitutes the polishing wheel of the present invention, whereupon he may proceed with the polishing operation, without shifting to any other machine or device.

The exposed face of the abrasive cloth is sufficiently wide and sutliciently well anchored to guard against tearing in the absence of excessive heat, as the wheel is fed across the surface of the crankshaft journal, and the ice heat developed in the process is rapidly carried off by the metallic body and dispersed into the surrounding atmosphere.

While I have described my polishing wheel as being particularly adapted for use in connection with a special crankshaft grinder now on the market, I wish to have it understood, of course, that l desire to be protected on my invention no matter in what connection it is used.

lI claim:

f A polishing wheel of the character described comprising, a cylindrical block having a at end face with a central conical depression therein, and having an axial threaded hole communicatingwith said depression, an abrasive clothhaving a -rirnV sectionV adhesively secured upon said end face and being substantially commensurate therewith, and having a central conical section'tting in said depression and apertured over the hole, and a screw threaded into the hole and having a head with a conical underface bearing Von the conical section of the abrasive cloth for anchoring the latter and with a at top disposed below the surface of the rim section of the cloth, the block having a series of annular grooves in the cylindrical surface thereof to provide a series of annular nsvfor conducting heat away from the block and the rim section of the abrasive cloth when the latter is rotated at high References Cited in the ile of this patent UNITED STATES PATENTS 2,279,673 Graenser Apr. VY14, 1942 2,309,615 Sunnen Jan. 26, 1943 2,454,726 Tott NOV. 23, 1948 2,657,509

Turton et al. a Nov. 3, 1953 

